Exception Response - Hitachi SJ-P1 Series User Manual

Chapter 7
7.2.13

Exception response

The inverter returns a response to the request, but
if an error occurs in the request, it is to return an
exception response.
[Exception response]
(Example)
In case configuring nonexistent address to holding
registers using the Modbus function code "03h
(Read holding registers)", it is to return the
exception response shown below.
Address Blocks
0
1
2
Modbus TCP
3
header part
4
5
6
7 Modbus
data part
8
Hi: high order
Lo: low order
*1) When returning the exception response, being
configured adding "80h" to the function code of
the request.
■Function codes of exception response
Items
Transaction ID (Hi)
Transaction ID (Lo)
Protocol ID (Hi)
Protocol ID (Lo)
Data size (Hi)
Data size (Lo)
Unit ID
Function code *1)
Exception codes *2)
Request
01h
03h
05h
06h
0Fh
10h
17h
About the Modbus TCP
Code
15h
01h
00h
00h
00h
03h
FFh
83h ←
02h
Exception Response
7-17
In the case, 3 byte lengths
(address 6 through 8).
The function code in the
request: 03h plus 80h
81h
83h
85h
86h
8Fh
90h
97h